1. Field of the Invention
This invention relates to a water filter, and more particularly to a laminated modular water filter.
2. Description of the Related Art
Referring to FIG. 1, a spiral-wound-type first conventional water filer 1 is shown to include a filter film unit 103, which is disposed between a pair of supporting nets 104 that are wound fixedly on a porous inner pipe 105. An outer pipe 106 is disposed fixedly around the inner pipe 105, and has two ends that are provided with two fixed end caps 107, respectively. Although the filter 1 can filter water effectively, it cannot be cleaned by forcing water therethrough. Furthermore, because it is difficult to remove the film unit 103 from the inner and outerpipes 105, 106, the former can only be cleaned by chemical agents after the filter 1 has been in use for a long time, thereby resulting in an expensive film-cleaning process.
Referring to FIGS. 2 and 3, a tubular-type second conventional water filter 2 is shown to include a plurality of tubular filter films 201 that are disposed within a pipe 202, thereby defining a filtered-water passage 203 between the pipe 202 and the films 201. Right and left outlets 204, 205 are formed respectively in two end portions of the pipe 202, and are in fluid communication with the passage 203. The pipe 202 has a left end chamber 206 that is in fluid communication with the left ends of the films 201, and a right end chamber 206xe2x80x2 that is in fluid communication with the right ends of the films 201. When it is desired to filter raw water or sewage water, that is referred to as dirty water hereinafter, one of the end chambers 206, 206xe2x80x2 is closed, e.g. by means of a stop valve (not shown), and the dirty water is forced into the other one of the end chambers 206, 206xe2x80x2, e.g. by a pump (not shown). The dirty water seeps through the films 201 so as to flow into the passage 203, thereby forming filtered potable water, which flows from the filter 2 through the outlets 204, 205. When it is desired to clean the filter 2, the outlets 204, 205 are closed and the end chambers 206, 206xe2x80x2 are opened so that washing water can be forced into one of the end chambers 206, 206xe2x80x2 so as to flow through the water filter 2 and exit the other one of the end chambers 206, 206xe2x80x2. Although the water filter 2 can be cleaned effectively, when the sizes of the solid particles suspended in the dirty water to be processed are comparatively large, they are easily stuck within the films 201, thereby affecting adversely the filtering effect of the water filter 2.
FIG. 4 shows a capillary-tube type third conventional water filter 3, which is similar to the second conventional water filter 2 (see FIGS. 2 and 3) and which includes a plurality of tubular filter films 301 that are filled within a pipe 302. The third conventional water filter 3 has the same drawback as the second conventional water filter 2 (see FIGS. 2 and 3).
An object of this invention is to provide a laminated modular water filter with a plurality of filter units, the number of which can be increased when the dirty water to be filtered is comparatively dirty.
Anther object of this invention is to provide a laminated modular water filter with a plurality of filter units, which can be cleaned effectively by forcing water through the filter units in opposite directions.
Still another object of this invention is to provide a laminated modular water filter with a plurality of filter units, which can be easily dismounted for cleaning purposes.
According to this invention, a laminated modular water filter includes a top plate, a bottom plate and a plurality of superposed intermediate plates disposed between the top and bottom plates. Each adjacent pair of the top, intermediate and bottom plates are interconnected removably, and define an accommodating space therebetween, within which a filter unit is received fittingly. Each of the top and bottom plates has a central hole which is in fluid communication with central holes in the intermediate plates, and two side openings which are in fluid communication with annular outer passages units in the intermediate plates that are in fluid communication with the accommodating spaces. Each of the filter units includes two filter films interconnected along outer peripheries thereof, and a filter net disposed between the films so as to define a filtered-water passage between the films that is fluid communication with the central holes.
When it is desired to filter dirty water, the central hole and the openings in the bottom plate are closed, and the dirty water is forced into the openings in the top plate. The dirty water flows into the outer passage units in the intermediate plates and subsequently into the accommodating spaces so as to seep through the films, thereby forming filtered water in the filtered-water passages, which flows from the water filter through the central hole in the top plate.
When the water to be processed is comparatively dirty, the number of the intermediate plates and the filter units can be increased.
The water filter can be cleaned by:
(1) a forward washing method including the steps of closing the central holes in the top and bottom plates, and forcing washing water into the openings in the top plate so as to flow from the water filter through the openings in the bottom plate; or
(2) a reverse washing method including the steps of closing the central hole in the top plate, and forcing washing water into the central hole in the bottom plate so as to flow from the water filter through the openings in the top and bottom plates; or
(3) a dismount washing method including the steps of removing each of the filter units from the remaining parts of the water filter and washing the former.